An example of a coil component of the related art is described in Japanese Unexamined Patent Application Publication No. 2011-253888. The coil component includes a core and a winding, and the core is composed of a single body and is composed of the same magnetic material throughout. The core includes a pair of flanges and a winding core. The winding core connects one flange and the other flange to each other. The winding is composed of a copper wire coated with an insulating coating film. The winding is wound around the winding core.
The inventor of the present application found the following issue with the coil component of the related art. Since the core of the coil component of the related art is composed of a single magnetic material and the strength of the core does not vary depending on the location, damage may occur in parts of the core where stress concentrates.
In particular, stress is likely to concentrate around the flanges and a base portion of the winding core, and more specifically, stress is likely to concentrate in portions of the flanges where electrodes are formed, that is, on distal parts of end portions of the flanges on the mounting surface side of the flanges. Therefore, damage is likely to occur in such portions.
In particular, in recent years, in order to increase the frequency and speed of logic circuits and to conserve resources and electrical power, coil components have been becoming progressively smaller in size. Therefore, the strength of cores has decreased with the reduction in size of the cores and the issue of damage has become significant.